Take part in the Which? Car Survey 2018

In this guide

The Which? Car Survey 2018 is now open. Take part and not only could you win £2,500, but with your help, we'll find the most and least reliable cars on UK roads.

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

The2018 Which? Car Surveyis now open - and we need you to tell us about your car. The results will help us find the most and least reliable cars and car brands, and puts you in the running for the £2,500 prize (T&Cs apply).

Whether you car is a flawless angel or a dodgy motor dogged by issues, we want to hear about it.

For taking part in this year's survey, you have the chance of winning £2,500 (terms and conditions apply) - that's more than enough to pay for fuel for an entire year.

Why complete the survey? Because while our in-depth lab tests reveal a car’s strengths and weaknesses, they won’t tell us what it’s like to live with – and that’s where you come in.

Thanks to the information you share with us, we can reveal which cars and car brands are the most and least reliable, what faults a car's likely to have and how much it's likely to set you back at your local garage.

This means when the time comes to buy your next car, you can use our research to avoid an unreliable model that's going to leave you stranded at the side of the road.

Every year, tens of thousands of people complete our annualWhich? Car Survey. The information you provide is crucial, as we use it to pinpoint the most reliable new and used cars.

How the Which? Car Survey helps you

Once results are in, we update:

New and used car reviews - every review is updated with the latest reliability information. This means you'll know which cars you can trust, and which you can't

Car reliability checker - our interactive tool reveals the most common faults for hundreds of new and used cars, giving you an idea of how much you're likely to fork out for repair bills

Top cars of 2017 - our car experts will help you quickly pick the very best car for your needs, plus we reveal the models you should steer clear of

Finding the most reliable cars

Whether you’re buying a new car or something a little older, we can help you find a model you can rely on.

We dig as deeply as we can into each car’s track record, going back a maximum of eight years. To make sure we rate cars fairly, we classify every fault we hear about as one of the following:

Most-serious faults are major problems that are likely to result in a breakdown, are expensive to repair and likely to lead to the car being off the road for more than one day.

Serious faults are likely to result in a breakdown and will either be expensive to fix, or keep the car off the road for more than a day.

Medium-rated faults are likely to cause a breakdown, but not be expensive or time consuming to repair.

Less-serious faults are unlikely to require immediate repair work, but could still be costly to fix.

Least-serious faults are non-essential problems that require less than a day off the road, and are cheap to put right.

When manufacturers ask why a car has scored poorly in the survey, we share as much detail as we can to help them get to the root of a problem. So these results not only help us compare different cars, they also give carmakers a reason to keep evolving and improving their products.

Best cars to drive in the UK

Satisfaction counts for an awful lot when it comes to customer loyalty. A happy owner is likely to buy another car from the same manufacturer and wholeheartedly recommend it to others.

That’s precisely why our survey asks owners to rate (out of five) how satisfied they are with their car, and also how likely they are to recommend it to a friend. By combining the responses to these two questions, we’re able to award each car a customer score as a percentage.